Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Molality question

  1. Feb 6, 2005 #1
    How do I find the molality of an aqueous solution containing 1g/L of a certain protein with molar mass 9.0 x 10^4 g/mol if the density of the solution is 1g/(cm^3)??
     
  2. jcsd
  3. Feb 6, 2005 #2

    chem_tr

    User Avatar
    Science Advisor
    Gold Member

    Molality is expressed with mole of the solute in one kilogram of solution. Try this approach first.
     
  4. Feb 6, 2005 #3
    My book says molality is moles of solute over kilograms solvent.

    My question/problem is how to find the kilograms of solvent :surprised
     
  5. Feb 6, 2005 #4

    dextercioby

    User Avatar
    Science Advisor
    Homework Helper

    U needn't.Use what Chem_Tr told u and a bit of logics.Just to get u started

    1g protein--------------------->1L solution
    1g solution--------------------->1 cc solution

    Question:
    1g protein--------------------->x Kg solution...

    Why didn't i pick "g solution" in the last line??Because u need to find moles protein/Kg solution...


    Daniel.
     
  6. Feb 7, 2005 #5

    Gokul43201

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    You may assume that adding a gram of protein to a liter of water does not change its volume (or the density).
     
  7. Feb 7, 2005 #6
    In that case...yes!--I can find it
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Molality question
  1. Molality and molarity (Replies: 2)

  2. Hybridisation question (Replies: 9)

Loading...